Method of and apparatus for winding yarn



Aug. 18, 1953 E. S. BALTHROP, JR

METHOD OF AND APPARATUS FOR WINDING YARN 5 Sheets-Sheet 1 Filed Feb. 8,1947 INVENTOR 4 905.5 Til/POP, (/1

A TTORNEY 1953 E. s. BALTHROP, JR 2,649,254

METHOD OF AND APPARATUS FOR WINDING YARN Filed Feb. 8, 1947 5Sheets-Sheet 2 INVENTOR.

Aug. 18, 1953 E. s. BALTHROP, JR 2,649,254

METHOD OF AND APPARATUS FOR WINDING YARN! Filed Feb. 8, 1947 5Sheets-Sheet 3 IN V EN TOR.

j I l A TTOE/VE) Z205 5,44 771 901; (/R. W fVM Aug. 18, 1953 E. s.BALTHROP, JR

. METHOD OF AND APPARATUS FOR WINDING YARN Aug. 18, 1953 E. s. BALTHROP,JR 2,649,254

METHOD OF AND APPARATUS FOR WINDING YARN Filed Feb. 8, 1947 5Sheets-Sheet 5 T FEE W2C; SE 523% wt ow. w im mm. m! 31 oi o2 N2 m- #208 m: N: 2: v9 09 mm mm mm vw v w Ow mh Nb mm Nw Ow ,mm mm at wv 3? mmmm mw vw ON 2 N o v INVENTOR:

EDWARD s. BALTHROP, JR. 6 94 7 m ATTORNEY Patented Aug. 18, 1953 METHODOF AND APPARATUS FOR WINDING YARN Edward S. Balthrop, Jr., Richmond,Va., assignor to E. I. du Pont de Nemours & Company, Wilmington, Del., acorporation of Delaware Application February 8, 1947, Serial No. 727,345

3 Claims.

This invention relates to a new and improved method of and apparatus forwinding yarn. More particularly, it relates to a method of and apparatusfor producing a smoothly wound package of heavy denier yarn in a formsuch as a bobbin.

In the winding of threads to a take-up package or bobbin, it isfrequently desirable to employ a face drive for the bobbin and aconstant thread. speed for the yarn supply. The yarn is disposed uponthe bobbin by the reciprocating action of a traverse guide. Thereciprocating motion is provided to distribute this yarn uniformly uponthe bobbin by its lateral motion across the bobbin face. However, theyarn may not be so distributed completely because of the occurrence ofnumerous bulges or protruding geometric patterns produced by periodicdeviation of the nature of thread enrollment from a random to arepetitive path upon the bobbin surface. These patterns, which standout, may be produced pe riodically throughout the progress of thewinding and result because of the periodic occurrence of certainrelations between the changing rate of rotation upon the bobbin in R. P.M. and the constant rate of oscillation of the traverse in strokes perminute.

When a constant thread supply speed is em ployed, the rate of rotationof the bobbin changes continuously in order that a constant peripheralspeed may be maintained, and therefore the relationship between bobbinR. P. M. and traverse frequency changes continuously. The principalrepeating pattern of thread enrollment is termed a ribbon wind. guidelays thread upon the bobbin in the same peripheral location on eachsucceeding stroke, or when the thread is laid essentially alongside theprevious helix, forming a band or ribbon. This is possible whenever theconstantly changing speed of rotation of the bobbin adjusts itself topresent the same point on the bobbin face to the traverse guide onconsecutive revolutions or, in other words, whenever the speed of thebobbin rotation in R. P. M. is a multiple of, or when the traverse speedis a divisor of, the bobbin R. P. M. There can be many of such values,resulting in many of such ribbon winds of varying degrees of severitythroughout the winding of the bobbin.

The recurrent patterns are caused not only when the successive helicesare laid essentially parallel and adjacent to or on top of the precedinghelices producing a primary pattern, but also when harmonics of thesefundamental p ir It occurs when the traverse terns are formed. Theseharmonics are characterized by the laying of only the second, third orfourth turns and so on repeatedly alongside or on top of the precedingor reference turn. In these wind effects of ribbon-like nature, theturns which should be laid at random are bunched together in a helicalband and thereby produce a bulge, leaving those parts of the bobbinperiphery lying outside the helical band without benefit of yarnlay-down to increase the diameter of those segments. Also, the crossingpoints of the turns of this helical band, being of double thickness,accentuate the bulge.

These ribbon winds handicap proper winding. They represent areas ofhigher relative compactness than adjacent band-free areas. On facedrivenwinders, the ribbon-like bulges produce bouncing of the bobbins upon thedriving rolls, damaging yarn and causing a loss of speed control due tothe uncontrolled skidding between the package and the roll. Also, theserelatively higher density areas are objectionable when the yarn inpackage form is to be treated with appropriate liquids because theyrequire a longer period of time for the penetration of treating liquids.They also serves as planes of cleavage, allowing the portions of yarnabove and below to slide axially over each other. Ribbon winds occurwith more or less severity in all yarn bobbins wound with a sufiicientlylarge change in the relationship of bobbin and traverse guide speed topermit the necessary coordination unless some mechanism is employed toavoid them. Those packages, and particularly large poundage packages,which change very little in diameter with respect to time, prolong andincrease intensity of the ribbon wind when formed.

Conventional methods employed to prevent the formation of these ribbonwinds on face-driven packages as well as non-face-driven packages wereof two types. Each employed a different type of mechanism. In the firstof these, the traverse guide drive was positively connected to thebobbin drive through a compensating mechanism which continuouslyadjusted the traverse speed at a linear rate to prevent theribbonforming coordination. In the case of a non-facedriven bobbin, suchas a cone winder, the traverse drive was connected to the yarn packagedrive with a gear train of a fixed ratio. Such compensation or fixedratio maintained the value of the quotient of bobbin R. P. M. divided bytraverse speed, which may be, for example, a compound decimal fractionin which at least the first two places in the decimal have values otherthan zero. In this way, the number of times that any one point on thebobbin periphery was opposed to the traverse guide was negligible.

In the second type, a mechanism called a ribbon breaker which changedthe traverse frequency in a pulsating manner was employed when it wasnot desirable to use a positive connection between bobbin and traverse.Such ribbon breakers employed an essentially rectangular rate of changeof traverse guide frequency. The amount of change was equal on bothhalves of the oscillatory cycle and the cycles were of equal period onsuccessive repetitions. Each cycle was very short and had considerabledwell at each repeating cycle. In other words, such ribbon breakersemployed essentially a simple harmonic type of motion to produce anessentially simple harmonic rate of change of the traverse frequencyand, in consequence, produced a considerable period of essentially zerochange of traverse rate at the terminal values of the harmonic motioncycle. Such a ribbon breaker scattered the ribbon winds into segments bychanging the ratio of traverse guide oscillation rate to bobbinrotational speed in a manner more rapid than occurred through naturaldecrease in bobbin speed alone. However, coincidence or superimposing ofthe segments occurred when the scattered pattern on one ribbon breakercycle was repeated upon the second cycle with essentially zero change inbobbin diameter as affected the peripheral location of the first turn ofyarn in each cycle. As previously mentinned, the coincidence andsuperimposition of the segments resulted in the objectionable bulges orprotuberances.

Additionally, the normal ribbon breakers were not eflicient inpreventing ribbon wind since it was possible for the ribbon-breakingmechanism to dwell and produce no change in Wind during the time inwhich a ribbon was forming. This was particularly objectionable on largedenier wet yarn packages because the proximity of even a few turns ofhelical coincident yarn resembling a ribbon was sufficient to beobjectionable due to their excessive protuberance from the otherwiseuniform package or bobbin. In general, the efiectiveness of the normalribbon breaker depended on the conditions of winding, such as averagetraverse rate to bobbin speed ratio, hereafter called wind ratio, sizeof package of yarn, size of yarn wound, and percent of moisture.

In the winding of heavy denier wet yarn upon large packages, the use ofgang doiiing was imperative on a multiposition machine with thefirst-mentioned system. Gang doffing with its limitations on processingflexibility was not required with the second system, but the size ofthread and the size of yarn package employed were not optimum for goodribbon breaker action and the wind ratio was of a value close enough tounity to be extremely critical. A regular ribbon breaker was inefiectivewith these conditions.

Wind ratios approaching a, value of 7 or less together with the heavydenier thread are very conducive to the formation of bounce-producingribbons. It is within this range of wind ratio values that it isnecessary to operate with wet yarn in order to prevent slumping down ofthe bobbin shoulders. This prevents selecting less critical ratios inwhich conventional ribbon breakers are eiiective.

An object of this invention is to provide a new and improved method ofand apparatus for producing a smoothly wound package of yarn.

Another object of this invention is to provide a new and improved methodof and apparatus for producing a smoothly wound package of heavy denierwet yarn in the form of a bobbi An additional object of this inventionis to provide a method of and apparatus for counteracting the formationof the ribbon winds which normal ribbon-breaking mechanisms have beenunable to prevent.

A further object of this invention is to provide a method of andapparatus for preventing ribbon winds which may be formed by theconventional ribbon breaker action when it coordinates with the naturalthread lay-down point at wind ratios other than those of ribbon winds.

A still further object of this invention is to provide a method of andapparatus for preventing the coincidence or superimposing of ribbonwinds that are scattered by regular ribbon breaker action.

A still further object of this invention is to provide a method of andapparatus for utilizing an increased degree of randomness of thetraverse motion to disperse recurring patterns of other than normalribbon wind character which result because of the continuance of windingat an essentially slow changing average wind ratio value.

Other and additional objects will become apparent hereinafter.

The objects of the invention are accomplished, in general, by constantlychanging the rate of change of the traverse frequency and constantlyvarying the duration of the cycle of change during the traversefrequency.

The necessary degree of randomness and extent of range for the values ofthe wind ratio is provided by the conjoint use of two independentcooperating mechanisms, herein called a ribbon breaker and a windbreaker. Herein, a ribbon breaker is the mechanism which disperses orscatters the successive helices in a ribbon wind into segments; and awind breaker is the mechanism which gradually changes the wind ratioslowly over a considerable range of at least l, /2 full number ratiovalues independently of the natural change in wind ratio due to thechange in the diameter of the package. It is to be noted that thisfluctuation of at least 1% full number ratio values occurs aconsiderable number of times during the package winding. The windbreaker is independent of the ribbon breaker. To illustrate, based onthe figures given in Example I, the bobbin R. P. M. at the start isabout 318. The base traverse speed is 42 strokes per minute.Accordingly, the wind ratio, defined as the bobbin R. P. M. divided bythe traverse speed, is about 7.38 at the start. During wind-up thebobbin R. P. M. is diminished as the cake builds up to maintain threadspeed constant. After, say, about five minutes the bobbin speed is about316 R. P. M. The wind ratio would then be (3l6+4=2.5) about 7.33. Thisnatural change is then about 0.05. However, the traverse speed ischanged in accordance with this invention, as shown in Example I, to amaximum of 58.5 strokes per minute. The wind ratio, accounting for thischange in traverse speed, is (3l6+58.5) about 5.40. The

diilerence ('1.385.40) is 1.98 and subtracting 0.05, the natural change,the change ratio, in-

dependent of this natural change, is 1.93 which is more than 1.5 fullnumber ratio value.

By changing the wind ratio slowly over a considerable range, scatteredribbon segments are not superimposed to form bulges by the recurrentactions of the ribbon breaker. Protuberant crossings characteristic ofcontinued winding in one particular ratio at a value close to but notwithin the range of the ribbon wind are interspersed with other winds ofsimilar character istics but which have their bulges located in otherpoints on the periphery, with the result that such intermingling smoothsout the bobbin contour.

The combination of the ribbon breaker and the wind breaker of thisinvention produces a curvilinear rate of change of traverse frequencywith essentially zero dwell at the reversal points and changes theduration of the cycle of repetition or period in successive cycles. Thiscurvilinear rate of change and its irregular increment of changeeliminate the ribbon effect which the conventional ribbon breakers withtheir constant rate of change and constant increment of change will tendto produce by virtue of their own action.

In carrying out the invention, yarn is directed onto a face-drivenbobbin by a traverse guide oscillated laterally across the face of thebobbin by a cam that is driven by a mechanical variable speed drive inwhich the speed is varied in accordance with the conjoint action of theribbon breaker and wind breaker of this invention. The variable speeddrive, in one embodiment of the invention, is a P. I. V. drive whereinthe speed of the output shaft is varied by oscillating the speed-controlshaft thereof in accordance with the action of the conjoint action ofthe ribbon breaker and wind breaker of this invention. If desired, theconjoint action of the ribbon breaker and the wind breaker can beamplified by a gear train or a differental gear, in which event theoutput shaft of the gear train or differential gear is coupled to thespeed-control shaft of the P. I. V. drive.

The ribbon breaker action is provided by means of a timing mechanism,such as a ribbon breaker cam and a ribbon breaker cam follower, and thedesired rates of change in the rate of rotation and extent of rise ofthe ribbon breaker cam are translated into oscillating motion in thefollower shaft. The contour of the ribbon breaker cam is such as toproduce a short period, high intensity, change of rate, oscillatoryribbon breaker action to change the traverse rate in the same manner asis shown by the irregular periphery of the ribbon breaker cam in Figure8. The design of the ribbon breaker cam is also such that essentiallyinstantaneous cycle reversals are obtained.

The wind breaker action is also provided by a timing mechanism, such asa wind breaker cam and wind breaker cam follower. The contour of thewind breaker cam is such as produces a change in traverse speed of anintensity approximately equal to but of much longer duration of cyclethan that of the ribbon breaker cam. The contour of the wind breaker camis such that essentially instantaneous cycle reversals are obtained.

The two cam follower oscillations, which vary as to time and degree ofrotation, are each connected to a shaft which is eared to the controlshaft of the P. I. V. drive. By this arrangement, either the ribbonbreaker cam or the wind breaker cam can move the P. I. V. control shaftindependently of the other, but the resulting motion caused by thecombined effect has a rate and direction of rotation which is aninstantaneous sum or vector resultant of the directions and magnitudesof motion of the wind and breaker motions. Thereby, the motions are saidto be added geometrically. Thi geometric sum of the traverse speedincrements is always positive or tends to increase the speed of thetraverse at a rate sufiiciently high to scatter a ribbon wind except forthe essentially instantaneous reversals, which are negligible.

The ribbon breaker cam rotates more rapidly than the wind breaker cam.An acceptable rate will be determined by the size of the yarn beingwound on the bobbin. The ribbon breaker cam may or may not provide fordwell at the end of the throw, but it does provide a gradual rise in thecontour followed by a quick return, to the follower starting point afterreaching the maximum rise. Additionally, provision for a faster thannormal rate of rise from the low position of the follower to someintermediate value may be made to guard against lost motion dwell in theP. I. V. control shaft due to wear.

The wind breaker cam employs the same essential features of contour ofthe ribbon breaker cam. It rotates, however, at a slower rate and has adifferent increment of rise than the ribbon breaker cam. As in the caseof the ribbon breaker cam, the wind breaker cam also has its incrementof rise and rate of rotation dictated by the particular type ofproduction being wound on the bobbin.

The wind breaker cooperates with the ribbon breaker to give sufficientrandomness to its action with reference to both duration and rate tomore effectively break a ribbon. The wind breaker also distributespatterns of other than ribbon-like nature by means of its longer cycleand it is assisted by the cooperation of the ribbon breaker to give it(the wind breaker) more randomness. The increased randomness preventsribbon winds of the type which may be formed by the conventional ribbonbreaker action when it coordinates with the natural progression of thethread lay-down at wind ratios other than those of ribbon winds.

The invention will be more clearly understood by reference to thefollowing detailed description when taken in connection with theaccompanying drawings, in which:

Figure 1 is a plan view of the invention, showing only one windingposition;

Figure 2 is a section taken on the line 22 of Figure l;

Figure 3 is a section taken on the line 33 of Figure 1;

Figure 4 is an elevation of Figure 1;

Figure 5 is a plan view of a modified form of the invention, the bobbin,the traverse and the traverse cam being omitted for convenience;

Figure 6 is an end View of the apparatus shown in Figure 5;

Figure 7 is a side view of the apparatus shown in Figure 5;

Figure 8 is a schematic arrangement illustrating the contours of theribbon breaker and wind breaker cams.

Figure 9 illustrates the yarn lay down occurring when a conventionalbreaker is used alone; and

Figure 10 illustrates the yarn lay down occurring when the wind andribbon breaker combination of this invention is used and this figureshows the irregular increment of change resulting in elimination ofribbons.

Fig. 11 shows the arrangement for multiple winding positions.

Referring now to the drawings, wherein like reference numerals designatelike parts, the reference numeral 2 designates a bobbin which is rotatedabout its horizontal axis by constant speed face-driving rolls of thewell-known type 2a, as shown in Figure 11. A thread, not shown, is fedfrom a suitable source of supply to a traverse guide 4 which is carriedat one end of a traverse arm 6. The other end of the traverse arm 6 issecured to a traverse support 8 which, in turn, is secured onto atraverse bar it. The traverse bar it is slidably mounted in a pluralityof traverse guides H arranged in spaced relationship. Each traverseguide is at the top of a support 13, which is appropriately secured atits bottom to a base it.

It is to be understood that the above is one position of a machinewherein there is a plurality of bobbons driven from a single series offace-driving rolls at constant speed, and each bobbin receives yarn as asingle end from a warp sheet of a plurality of ends traveling atidentical speeds. In such machine, a traverse guide cooperates with eachbobbin but the traverse bar is common to all.

The traverse bar I!) is provided with a follower l6 which cooperateswith a traverse cam ii! of such design that during operation thetraverse bar l0, and hence the traverse guide l, are reciprocatedlaterally across the face of the bobbin 2. The traverse cam i8 issecured onto a shaft 28, the ends of which are rotatably mounted inbearings 2i. A gear 22 secured to the shaft 29 is in cooperativerelationship with a gear 24 carried on the output shaft 25 of a P. I. V.drive, generally indicated by the reference numeral 28. The referencenumeral 35 designates the input shaft and the reference numeral 32designates the control shaft of the P. I. V. drive. Since the details ofconstruction of the P. I. V. drive are well known, and such details ofconstruction thereof form no part of this invention, a detaileddescription is not believed necessary. The input shaft 38 of the P. I.V. drive 28 is coupled to a shaft 35 which is appropriately mounted inbearings 33 carried by the base M. A gear 42 on one end of the shaft 38is driven by a gear 44 carried at the end of a motor shaft 46.

From the description of the apparatus thus far, it is manifest that thetraverse cam I8 will be driven by the output shaft 26 of the P. I. V.drive and the traverse bar Hi will be oscillated at a frequencydetermined by the rate of rotation of the P. I. V. shaft 26 and thegears 22 and 2d. The rate of rotation of the P. I. V. output shaft 23 iscontrolled in the well-known manner by the control shaft 32. The controlshaft 32 is oscillated in accordance with the actuation thereof by themeans constituting this invention, as hereinafter described.

The P. I. V. control shaft 32 is provided with a gear 50 which is incooperative relationship with a gear 52 carried on an idler shaft 54rotatably mounted in bearings 56 mounted on the base M. The shaft 54 isoscillated by means, hereinafter described, whereby the control shaft 32of the P. I. V. drive is moved in accordance therewith.

A ribbon breaker cam 68 is rotatably mounted on an output shaft 62 of areducing gear train (not shown) in the gear box 64, which isappropriately mounted on the base M. The input shaft 66 of such geartrain is provided with a flanged pulley 68 which is driven by a V-beltit from a pulley 12 on the main drive shaft 36. A cam follower i6 iscarried on an arm 18, the lower end of which is pivotally mounted on ashaft 39 mounted in bearings 82 secured to the base Hi. Adjacent itstop, the arm 18 is pivotally secured between the legs of a U-shaped link84. The bottom of the lnk 8 3 is secured to one end of a chain 85 which,as shown in Figure 3, passes beneath an idler sprocket 88, over asprocket 90, around an idler sprocket 92, and the other end thereofsecured to one end of a spring 9%, which is secured at its other end inan appropriate support 95. The sprocket 88 is mounted on a shaft 98rotatably mounted in bearings I on the base. The sprocket 86 is mountedon one arm of a lever I82, which will be hereafter more fully described.The sprocket 92 is secured onto the shaft 54.

A wind breaker cam lid is rotatably mounted on an output shaft H2 of areducing gear train in the gear box H4 appropriately secured on asupport H5. The input shaft 518 is provided with a flanged pulley l 58which is driven by the V-belt H3. A Windbreaker cam roller i228cooperates with the wind breaker cam Hi The wind breaker cam roller I20is carried at one end of the lever H12 which is pivotally mounted atI24.

It is manifest that the control shaft 32 of the P. I. V. drive 28 willbe oscillated in accordance with the oscillations of the shaft 54 whichare amplified by the gears 56 and 52. The oscillations of the shaft 54are the result of the geometric addition of the motions of the ribbonbreaker cam 60 and the wind breaker cam MD, as hereinbefore explained.

The rate of rotation and the contour of the ribbon breaker cam (it aresuch as to produce a short period, high intensity change of rate,oscillatory ribbon breaker action to change the traverse rate in thesame manner and also to provide essentially instantaneous cyclereversals (see Figures 4 and 8). The wind breaker cam H0 is rotated atsuch a rate and is of such a contour as to produce a change in traversespeed of an intensity approximately equal to but of much longer durationthan that of the ribbon breaker cam. The wind breaker cam is also ofsuch design that essentially instantaneous cycle reversals are obtained.In general, the wind breaker cam H9 employs the same essential featuresof contour of the ribbon breaker cam 69, but it operates at a slowerrate and has a different increment of rise than the ribbon breaker cam50. In both cams, the respective increments of rise and the rate ofrotation thereof are dictated by the particular type of production beingwound on the bobbin.

The contour of the ribbon breaker and wind breaker cams is generallyshown in Figure 8, wherein mean speed denotes the specified value of thetraverse bar cam when the wind breaker cam is at the set point and theribbon breaker cam is at the set point corresponding to 107 past the 0point. Mean speed equals the number of revolutions per minute of the camof the traverse bar when the wind breaker cam is in the mean speedposition and the ribbon breaker cam is starting through the linear 253travel.

The arrangement is such that the change in P. I. V. causes aproportionate speed change in 9 the traverse bar action, the total speedchange being 37.7%.

In a modified form of the invention, the traverse bar is varied in itsrate of oscillation through the action of a P. I. V. drive which iscontrolled by a ribbon breaker and wind breaker through a differentialgear drive. In such embodiment, the output shaft of the differentialgear drive is connected to the control shaft of the P. I. V. drive. Theribbon breaker follower is attached to a shaft of a differential gear ofthe differential gear drive while the wind breaker cam is also coupledto the differential gear. The arrangement is such that the oscillationof either of the cam followers by the respective cam produces partialrotation of the output shaft of the differential. Preferably, suchrotation of the output differential shaft is amplified by a gear setbefore it is transferred to the P. I. V. control shaft.

Referring now to Figures -7, wherein the modified form is shown, theinput shaft of the P. I. V. drive 28 is driven as in the previouslydescribed modification, and the output shaft 26 of the P. I. V. drive 28drives the traverse cam I8, as also described in the previousembodiment. The control shaft 32 of the P. I. V. drive 28 is driven fromthe output shaft I of a differential gear drive, generally designated bythe reference numeral I42, by the gear sets I44 and M6. Since thedetails of construction of the differential gear drive are well known,and such details of construction do not form any part of this invention,it is deemed unnecessary to describe the differential gear drive indetail.

A ribbon breaker cam I48 is secured to the output shaft I50 of a speedreducer I52, the input shaft I54 of which carries a flanged pulley I56.A ribbon breaker cam follower I58 is carried at the upper end of a leverI60 which is secured to a shaft I62 of a differential gear of thedifferential gear drive. The lower end of the lever I60 is secured toone end of a spring I64.

A Wind breaker cam I14 i rotatably mounted on the output shaft I'IS of aspeed reducer I18, the input shaft I of which is provided with a flangedpulley I82. A wind breaker cam follower I is carried at the upper end ofa lever I9 2 which is secured to a shaft I94, which is coupled to thedifferential gear in the differential gear drive I42.

A belt I96 passing over pulleys I 56 and I82, and which is driven fromthe input shaft 30 0f the P. I. V. drive in any convenient manner,operates the speed reducers I52 and I18 at constant speed.

In this embodiment, the wind breaker cam has a cycle of 5 minutes andchanges the speed of the P, I. V. output 24% when the ribbon breaker camis stationary. This gives :12 change from mean speed. The ribbon breakercam speed is 4 R. P. M. and it changes the P. I. V. output speed 12 /2%When the wind breaker cam is stationary and is cut to give a cycle asfollows: Low point to a point 35 of rotation to give a P. I. V. increaseof l /2%, not of necessity a linear motion; from 35-350, there is astraight line motion, giving a speed increase to the P. I. V. output of8% from 350-360, the speed is returned to the starting value. The l /2%speed increment in cam contour is to pick up P. I. V. control screwbacklash.

The following specific examples are given to illustrate certain specificembodiments of the invention, it being understood that the invention isnot restricted thereto:

10 Example I On each of a. plurality of bobbins, 6" in diameter and 10in length, without heads, and driven from a single series offace-driving rolls at constant speed of 6,000 per minute, is wound an1100-denier rayon yarn, of either zero twist or twisted yarn with %-300%moisture as a single end from a warp sheet formed of a plurality of suchyarns travelling at identical speed, to form a package in which thefinal bobbin diameter is approximately 9.5".

The ribbon breaker cycle is 12.5 seconds as determined by a rate ofrotation of the ribbon breaker cam of i8 R. P. M. The speed changeconsists of zero change for approximately 1.8 secends; a 9% increase inapproximately 1.5 seconds; a uniform rate increase of 10% inapproximately 8.8 seconds; and a decrease to the initial value in theremainder of the 12.5 seconds. The dwell is to provide approximately 1traverse strokes at zero speed change for the ribbon breaker, permitting the lead in the helix angle to be shifted to the oppositeshoulder of the bobbin. The rise of 9% in 1.5 seconds is to pick up thelost motion in the mechanical linkage which might develop through wear.The increase in speed of 10% in 8.8 seconds is the important speedchange range and the quick return is provided as required, for thereasons previously explained.

The wind breaker has a complete cycle of speed increase and decrease in5 minutes. This speed change is distributed as follows: 25 seconds speedincrease, giving 2.7% change in traverse speed, at any rate, linear orotherwise; 4.17 minutes speed increase at an essentially uniform rate,giving a 16% change in traverse rate; and finally, a reversal to the camstarting point, giving an 18.7% change in traverse rate in 25 seconds.

The base traverse speed is selected as 42 1 strokes per minute since ithas been shown experimentally that this lower speed can be used if thesubsequent change is rapid. The maximum traverse speed then becomes (42/2) strokes per minute.

Since the speeds of rotation of the two cams are dissimilar, it will beseen that the overall sum of instantaneous value of the traverse speedvaries on successive ribbon breaker cycles. It will also be seen thatthe length of the ribbon breaker cycle varies because of the effect ofreversal of the wind breaker.

In Figure 9 the yarn laydown using a conventional breaker is shown. Ascan be seen, A, B, A and B are equal to each other. Thus, the successivelayer of yarn is directly on top of the previous laydown and the medianpoint of a ribbon is formed.

In Figure 10 is shown graphically the yarn laydown occurring in severalribbon breaker cycles during which cycles the wind breaker speeds arechanging. There is an irregular increment of change and ribbons areeliminated.

Packages of wet yarn containing the equivalent of 4 to 7 pounds of dryyarn wound in this manner possessed smooth uniform surfaces.

Eatample II Winding of 1100-denier rayon yarn, with 150%300% moisture ata speed of 3600 per minute and upon 6" diameter x 10" long bobbin cores,without heads, and having a yarn buildup to 9 /2" diameter.

The equipment is the same as in Example I,

except that the basic starting speed of 42 strokes per minute is changedto give the same wind ratio value at 3600 per minute as obtained with 42/2 strokes on 6000" per minute. This is 25 /2 strokes per minute. Thecycle times of both ribbon breaker and wind breaker can be the same orcan be extended an amount equal to the ratio of the speeds making theribbon breaker cycle 2.8 seconds and the wind breaker 7.5 minutes. Thespeed change increments percentagewise are retained as well as the camcontours.

Example III Winding of ZZOO-denier rayon yarn, with 150%-300% moistureat 3600" per minute on 6" diameter x 10" long bobbins producing afinished package size of 9 diameter. The equipment is the same as inExample I, except that the cycles and increments of change of thetraverse bar speed as determined by the ribbon and wind breakers arechanged.

Since the rate of yarn deposit is established in Example I forUGO-denier yarn at 6000" per minute and the wind breaker cycle is basedon the length of duration of a ribbon wind at this rate of build-up, thevalue must be changed when winding at a difierent speed and denier.Therefore,

1 42 X6000 2o, strokes per minute Example I V 5 X =42 minutes Winding ofBOO-denier rayon yarn, with 1509 300% moisture at 6000" per minute on 6diameter x 16" long cores to a finished diameter of 9V2 using no headson the bobbins.

The equipment is the same as in Example I, except that the traversespeed change cycle times of the ribbon and wind breaker units arealtered. The basic traverse speed remains at 42 strokes per minute.

The rate of yarn build-up for llOO-denier at 6000" per minute iscompensated for by a 5 minute wind breaker cycle. Since 300-denierbuilds up 3.67 times less rapidly, the cycle should be 5 3.67, or 18 /3minutes.

Since the traverse speed. change rate must be at least 20% per minuteand the average speed change of the ribbon breaker-wind breakercombination is of this approximate value when the wind breaker cycle islengthened, the ribbon breaker cycle and increments of change remain thesame as in Example I.

Since the eilect of the wind breaker upon the cycle length of the ribbonbreaker is felt less often because of the lengthening of the windbreaker cycle, the ribbon breaker cam must be driven from the traversebar P. I. V. variable speed shaftso arranged that the cycle time of 12.5seconds is experienced when the wind breaker is at the low speed value.Thereby, the

variation in wind breaker in changing the traverse speed also changesthe speed of rotation of the ribbon breaker cam and, therefore, itslength of cycle.

In the examples, the use of rayon yarn of l5()%-300% moisture has beenset forth. The invention is equally efiective on either moist or dryyarn, or with yarns other than rayon, or strands of whatever nature.

The range of package sizes described is based on a 6" diameter core witha 10" length, but the bobbins can be any size or length as long as theprinciples employed in setting up the operation of the combination forMOO-denier yarn on the stated size of package are followed. For example,the selected length of time or duration of the wind breaker cycle andits increment of change is based on fundamental principles that can beappli d to any size of package. Similarly, the ribbon breaker is basedupon a 20% per minute rate of change for a shorter than 1 minuteduration to keep the total increase in speed low. Also, the minimumspeed of traverse is determined by the minimum helix angle expressed aswind ratio which can be used with a given yarn type, and this will notvary greatly with the size of the yarn package selected. With Wet rayon,this is approximately '7 to, 1 wind ratio.

Although the means for accomplishing the changes in speed described inthe examples is entirely mechanical, it may be hydraulic, electrical ormechanical, or any combination of these which will cause the speed ofoscillation of the traverse guide to vary as described. Instead of a P.I. V. drive, other drives, such as a direct current motor with theribbon and wind breaker oscillations controlling field resistors whichcontrol the speed, can. be used. Capacitance control of the firing of athyratron rectifier or inductance control can be employed to vary thecurrent to the motor, the change in capacitance or inductance beingaccomplished by the Wind and ribbon breakers which, in turn, may beelectronic capacitance timers.

The drives for the timing devices, such as cams, may be derived from anyconstant speed source. To obtain more effective ribbon breaking action,it is desirable to drive the ribbon breaker cycling device from thevariable speed side of the traverse drive as it is coupled to thetraverse cam. It is not imperative except as stated in Example IV.

Although the examples disclose the use of facedriven packages, theinvention can be used as a substitute for the less effectiveconventional ribbon breakers on any textile or other strand- Windingmachine which employs multiple positions with a common drive and acommon traverse, as for example an uptwister or a bobbin bucket-spinningmachine where exact wind or ratio does not characterize the winding.

Since it is obvious that many changes and modifications can be made inthe above-described details without departing from the nature and spiritof the invention, it is to be understood that the invention is not to belimited thereto except as set forth in the appended claims.

I claim:

I. n a yarn-winding machine having a plurality of winding units, avribbon breaker and a wind breaker with a common drive and a commonoscillating traverse, the combination comprising means for imparting ashort period oi" high intensity change in the oscillating action ofsaidribbon breaker; a second means for producing a chang in the actionof said wind breaker of approximately the same intensity as said ribbonbreaker but of longer duration; and means to transmit the geometricaddition of the change of said first means and the change of said secondmeans to said traverse.

2. In a yarn-winding machine having a plurality of winding units with acommon drive and a common oscillating traverse, the combinationcomprising a variable speed-control mechanism for driving said traverse;a ribbon breaker; a wind breaker; means for varying the speed of saidribbon breaker; means for varying the speed of said wind breaker; andmeans to vary the speed of said variable speed mechanism in cooperationwith said means for varying the speed of said ribbon breaker and withsaid means for varying the speed of said wind breaker to produce randomwinding of said yarn.

3. In a yarn-winding machine having a plurality of winding units with acommon drive and a. common oscillating traverse, the combinationcomprising a variable speed-control mechanism for driving said traverse;a ribbon breaker; a rotating cam for imparting a short period of highintensity change of rate in the oscillating action of said ribbonbreaker; a wind breaker; a second rotating cam for producing a change inspeed of said wind breaker of approximately the same intensity as thesaid change in speed of said ribbon breaker but of longer duration; andmeans to vary the speed of said speed-control mechanism in accordancewith the geometric addition of the said change in speed of said ribbonbreaker and the said change in speed of said Wind breaker.

EDWARD S. BALTHROP, JR.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 679,416 Craven July 30, 1901 1,234,388 Rand et a1 July 24,1917 1,397,905 Rhoades Nov. 22, 1921 1,728,413 Jones et a1 Sept. 17,1929 2,019,364 Schweizer Oct. 29, 1935 2,345,601 Hickes Apr. 4, 19442,358,294 Arterton et a1 Sept. 19, 1944

